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Shrub Rose 'Rainbow Knock Out'


Family: Rosaceae (ro-ZAY-see-ee) (Info)
Genus: Rosa (RO-zuh) (Info)
Cultivar: Rainbow Knock Out
Additional cultivar information:(PP17346, aka Rainbow Knock Out, RADcor)
Hybridized by Radler
Registered or introduced: 2005
» View all varieties of Roses




24-36 in. (60-90 cm)


24-36 in. (60-90 cm)


USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Bloom Color:

Apricot and apricot blend (ab)

Light pink (lp)

Bloom Shape:


Flower Fragrance:

No fragrance

Bloom Time:

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall

Mid Fall

Blooms repeatedly



Patent Information:


Other Details:

Resistant to black spot

Resistant to rust

Sets hips

Pruning Instructions:

Blooms on new wood; prune early to promote new growth

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

Propagation Methods:

From softwood cuttings

From semi-hardwood cuttings

From hardwood cuttings

By grafting

By budding

Foliage Color:

Unknown - Tell us

Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Unknown - Tell us

Where to Grow:

Unknown - Tell us


This plant has been said to grow in the following regions:

Williford, Arkansas

Forest Falls, California

San Jose, California

Baton Rouge, Louisiana

Roslindale, Massachusetts

Minneapolis, Minnesota

Southold, New York

Concord, North Carolina

Columbus, Ohio

Fort Mill, South Carolina

Knoxville, Tennessee

Copperas Cove, Texas

Richmond, Texas

Alexandria, Virginia

show all

Gardeners' Notes:


On Mar 5, 2015, DaylilySLP from Dearborn Heights, MI (Zone 6a) wrote:



On Oct 13, 2014, ckelisna from Tega Cay, SC wrote:

I've had them one year. I was attracted by the color of blooms but they stay small and don't last, leaving it looking unkempt. It's not nearly as big as other knockouts. I had to spray several times for aphids. I was counting on it growing without a lot of attention. Some stems had fungus and it was hard to shape. Many small branches developed tightly.


On Feb 17, 2014, coriaceous from ROSLINDALE, MA wrote:

Rainbow Knockout sheds its petals cleanly, but as the season progresses it builds up a surface layer of blackened sepals/spent flowers that makes the shrub look unkempt and distracts my eyes from the new flowers. Other Knockouts cover these with new growth, but Rainbow Knockout does not.

Petals fade to near white before dropping. I find this is a distraction and looks bad.

I suppose you could use hedge trimmers to take off the spent blooms, but that doesn't seem to be something most people are inclined to do. Or you could deadhead, but Knockouts were bred to be "no-deadheading-needed" roses.

Unlike other Knockouts, Rainbow Knockout produces a lot of dense thorny twiggy growth with interspersed winter dieback that's tedious to prune by conventio... read more


On Apr 20, 2012, paddleaddict from Chesapeake, VA wrote:

There are 14 rainbow knock-out roses lining the front of my southwest facing beds that stay covered with powdery mildew from early spring to first frost. I live in zone 8. They receive no overhead irrigation and are growing in full sun conditions. They have excellent air movement and only late afternoon shade. Other knock-outs nearby are stellar. The rainbows have been established now for about 8 years, and receive routine maintenance. Both my husband and I are professionals in horticulture, but cannot get any solid reasons for their continuing condition. We have 'many' other varieties of roses throughout our yard that are amazing. The rainbows flower wonderfully, but like I said are plagued with powdery mildew. We are not eager to nuke them as we've created a song bird 'sanctuary' and hop... read more


On Apr 1, 2012, Sandwichkatexan from Copperas Cove, TX wrote:

I have these planted in heavy shade and they still bloom like crazy . In my area they have no blackspot or mildew and they have beautiful hips in the winter . One of the few roses that will heavily bloom in shade .


On Oct 29, 2008, dovey from Columbus, OH (Zone 5b) wrote:

I like Rainbow Knockout, of all the knockout roses it's the prettiest. It makes a great choice for a tree rose.
It seems to enjoy a dryer climate over an area with high humidity.


On Jun 2, 2008, jetgirl from Alexandria, VA wrote:

I saw the Rainbow Knock Out rose at a nursery today, and the plants had significant MILDEW on the new growth (top 6", leaves and buds). The nursery is on a ridge with good air movement and all day sun. I think the supplier was Star Roses.


On Feb 9, 2007, mystic from Ewing, KY (Zone 6a) wrote:

2007 AARS (All-American Rose Selection) winner.